Machine for sharpening gear cutters



May 9, 1933. s EARL 1,908,476

MACHINE FOR SHARPENING GEAR CUTTERS Filed Dec. 18, 1950 5 Sheets-Sheet 2INVENTOR 56 267122. EQrZ Zz's ATTORN May' 9, 1933. s EARL 1,908,476

MACHINE FOR SHARPENING GEAR CUTTERS Filed Dec. 18, 1950 5 Sheets-Sheet 5inEl 4% law INVENTOR SckzzyZer HIQrZ BY his ATTORN May 9, 1933. s. H.EARL MACHINE FOR SHARPENING GEAR CUTTERS '5 Sheets-Sheet 4 Filed Dec.18, 1930 lNVENTOR 5072 Zei'HFQTZ 2Z ATTORNEY May 9, 1933. s. H. EARLMACHINE FOR SHARPENING GEAR CUTTERS Filed Dec. 18, 1950 5 Sheets-Sheet 5HVVA INVENTOR H Earl /s ATTORNE Patented May 9, 1933 UNITED STATESParent enter SCHUYLER H. EARL, OF ROCHESTER, NEW YORK, ASSEGNGR TOGLEASON WORKS, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK MACHINEFOR SHAR-PEHING GEAR CUTTERS Application filed December 18, 1930. SerialNo. 503,212.

The present invention relates to machines for sharpening cutting toolsand particularly to grinders for sharpening gear cutting tools.

The primary purpose of the present invention is to provide a practical,compact and relatively inexpensive machine for wet grinding gearcutters. This object of the invention is accomplished by providing amachine in which the movement of the cutting tool across the face of thegrinding wheel for sharpening the tool is a hand operation and in whichwater or another suitable coolant is continuously and copiously suppliedto the grinding wheel during the grinding operation. The present machineavoids all the objections to the old type of dry grinders as beingunsanitary, dangerous and nnhealthful while at the same time providing amachine which is essentially very simple and comparatively cheap.

The present invention has two difierent applications one is thesharpening of reciprocatory tools such as are employed on straight andskew bevel generators and other straight tooth gear cutting machines andthe other is the sharpening of face-mill gear cutters such as are usedon machines for cutting longitudinally curved tooth gears like spiralbevel and hypo-id gears. Heretofore separate machines have been requiredfor sharpening these two separate types of tools. The present inventionprovides not only an improved form of machine for both jobs, as pointedout above, but it is within the con" templation of the presentinvention, also, to use One machine for sharpening both reciprocatorytools and face mill cutters. Thus a further feature of the presentinvention is the possible material saving which may be effected in theamount of equipment required in a gear cutting shop for sharpening thecutting tools.

In bevel gear generators and other gear cutting machines employingreciprocating cutting tools, there are ordinarily two tools used onetool cutting one side tooth face of. the gear blank and the other toolcutting the opposite side tooth face. Grinders built prior to thisinvention. for grinding these tools were so constructed that separategrinding wheels were required to sharpen the two tools simultaneously.In the present machine both tools can be sharpened simultaneously withone wheel. Thus an added feature of the invention applicable to theFigure 2 is a plan view of this machine on a somewhat enlarged scale;

Figure 3 is a fragmentary plan view showing the machine arranged forsharpening a face mill gear cutter, parts of the cutter support beingshown in section;

Figure t is a front elevational view of the cutter support shown inFigure 3, parts being shown in section;

Figure 5 is a section on the line 55 of Figure 4;

Figure 6 is a side elevational view showing details of the constructionof the face mill cutter support shown in Figures 3 and l;

Figure 7 is a detail View showing the method of gaging the height of thediamond dresser used in dressing the grinding wheel employed forsharpening the face mill cutters;

Figure 8 is a section on the line 88 of Figure 2;

Figure 9 is a fragmentary view on an enlarged scale illustrating thesharpening of a face mill cutter;

Figure 10 is a corresponding view illustrating the sharpening of areciprocatory cutting tool; I

Figure 11 is a View taken at right angles to Figure 10 and showingfurther details of the holder for the reciprocatory cutting tool;

Figure 12 is a fragmentary sectional view showing details of thereservoir for the coolant;

Figure 13 is a section on the line 1313 of Figure 4; and

Figures 14 and 15 are perspective views of one blade of a face mill gearcutter and of a reciprocatory cutting tool, respectively, these beingtypical of the forms of tools to be ground -on the sharpening machine ofthe present invention.

In a machine built according to the preferred embodiment of thisinvention, the grinding wheel is mounted upon a vertical spindle whichis motor driven and continuously rotated during the operation of themachine. The cutting tools to be ground are secured to swingablesupports which are mounted in the base of the machine and are operatedby hand to move the cutting tools across the faceof the grinding wheelfor sharpening. A :ljustments are provided to permit positioning thetools so as to grind their front faces correctly to various angles as isrequired. Three tool supports maybe furnished with the machine, one formounting a face mill gear cutter and two for mounting the upper andlower tools of a. pair of reciprocatory gear cutting tools. The tworeciprocatory tools may be ground simultaneously with the'same wheel byswinging them simultaneously across the face of the wheel. A cup-shapedwheel is preferably employed when grinding the reciprocatory tools whilea dished wheel is preferably used when sharpening face mill cutters. Thesupport for the face mill cutters includes an indeXing mechanism whichpermits indexing the cutter head around to allow of sharpening of allthe blades of the cutter. A pump is provided with the machine and thispump is driven from the grinding wheel shaft to pump water or any othersuitable coolant continuously from a reservoir in the base of themachine onto the grinding wheel during the operation of the machine.

Referring to the drawings by numerals of reference, indicates the baseor frame of the machine. The base is formed with an integral column orupright 21. The upright and base are hollow but are provided withreinforcing ribs at suitable points to give the requisite strength. 'Asleeve or hearing mem ber 22 is secured in a vertical opening in thefront portion of the column 21. This sleeve or bearing member 22 has apressed fit in the opening in the column and is secured therein, also,by the shoulder 23. It is held against rotation in the opening by theset-screw 24.

The grinding wheel spindle 25 is journaled in anti friction bearings 26and 27 in the sleeve or hearin member 22. A labyrinth seal indicatedat'28 is secured to the lower end of the sleeve 22 to protect thebearings 27 against entrance of grit or dirt therein. The seal 28 issecured to the bearing member 22 by screws 29 while the anti-frictionbearings 27 are held in position against the seal by nuts 30. A nut 32(Fig. 1) threaded on the upper end of the spindle 25 serves to hold thebearing 26 in position against a shoulder formed on the spindle.

There is a cap-member 33 (Fig. 1) secured to the upper end of thebearing member 22 and surrounding the spindle 25. Keyed to the spindle25 above this cap-member is a pulley 34 and keyed to the spindle 25above the pulley 34 is a second pulley 35.

The grinding wheel spindle 25 is driven continuously during theoperation of the ma chine from a motor which is housed in the base 20 ofthe machine. There is a pulley 41 connected to the armature shaft of themotor and this pulley 41 drives the pulley 35 through the belt 42. Thedrive from the pulley 41'to the pulley 35 is a right-angular drive, thebelt 42passing over idler pulleys 43. These idlers 43 are secured to ashaft 44 that is suitably journaled in the upright or column 21. v

Secured within the column 21 is a bracket 50, to the lower end of whichis secured a centrifugal pump 51 (Figs. 1 and 12). The upper end of thebracket is secured to the upright 21 by bolts 52. The pump 51 is itselfsecured to the lower end of the bracket by screws 53. Journaled inanti-friction bearings 55 and 56 in the bracket 50 is the pumpshaft 57.The impeller or paddle 58 of the pump 51 is secured to the lower end ofthe shaft 57 by the nut 59. The pump is immersed in a reservoir 60 whichis kept filled with water or any other suitable coolant above the levelof the pump. The reservoir 60 is cast integral with the frame of themachine.

The pump-shaft 57 is driven continuously during the operation of themachine from the grinder spindle 25 through the pulley 32, the belt 62and the pulley 63 which is keyed to the upper end of the pump shaft 67and which is held thereon by the nut 65. The coolant is pumped from thereservoir 60 through the pipe 65 and branch pipes 66 to the grindingWheel to continuously force coolant on the wheel at opposite sidesthereof. A valve 68 i may be employed to control the rate of flow of thecoolant.

There are three post openings 70 formed in the base of the machine. Oneof these openings is adapted to receive the post on which a spiralcutter is mounted when such a cutter is to be sharpened. The other twoopenings are adapted to receive the posts which carry the supports forthe two reciprocatory tools when a pair of such tools are to besharpened. When sharpening a pair of reciprocatory tools, the post whichis adapted to carry the face mill cutter is removed from the machine andwhen a face mill cutter is to be sharpened, the posts which are adaptedI to carry the reciprocatory tools are removed from the machine.Suitable covers are provided to cover the several openings when not inuse.

I shall first describe the sharpening of a pair of reciprocatory gearcutting too-ls and reference will be had, then, first of all to Figures1, 2, 8, 10, 11 and 15. The pair of reciprocatory tools are ordinarilymade alike except that one tool of the pair is sharpened on one end andthe other tool of the pair on the other end. The sharpened end of eachtool constitutes its front face. The cutting edge of the tool is formedby the acute angular junction of the front face of the tool with one ofits side faces. This results from sharpening the tool with a front rakeor shear angle.

One of a pair of reciprocatory gear cutting tools 72 is shown in Figure15. The front face 7 5 of the tool intersects the side face 7 6 at anacute angle, the angle depending upon the front rake or shear angle ofthe tool. The sides of the tool are inclined to each other in accordancewith the pressure angle of the tool. The tool is of uniform sectionthroughout its length, the cutting clearance being obtained by incliningthe tool to the line of cut. Depending upon the material in the gears tobe cut, the tool may be ground with a hook or without a hook. A toolground with a hook is a tool whose front face is inclined rearwardlyfrom the tip of the tool to the base of the cutting portion thereof.

The two tool holders and 81 provided with the present machine forholding a pair of reciprocatory cutting tools are similarinconstruction. Each tool holder is formed with a tool receiving socket82. For cutting any usual material, there is a standard front rake angleindicated for reciprocatory gear cutting tools. As a matter ofconvenience, the tool holders provided with the present machine are madeso that when the tools are in position they are held at an angle to thegrinding wheel corresponding to the standard front rake or shear angle.Thus, the tool receiving sockets 82 formed in the holders 80 and 81extend diagonally from top to bottom of the holders and the angle whichthe center line of each socket makes with a vertical line in the zeroposition of adjustment of the holder is determined by the standard shearangle. 7

Each of the cutting tools 72 of a pair is rigidly clamped in the sockets82 of its respective tool holders 80 and 81 by the clamping screws 84which thread in the holders 80 and 81 and which are provided at theirinner ends with enlarged heads 85 that engage the body portions of thetools.

The clamping screws are manipulated by the handles 86.

I Each of the tool holders 80 and 81 is mounted for angular adjustmentupon an angle bracket which is formed with two faces 91 and 92 thatextend at right angles to one another. There is'an angularly adjustabledisc 93. mounted on each of the brackets 90 and interposed between theface 91 of the bracket and the opposed face of the associated to'olholder 80 or 81, as the case may be. 7

Each of the tool holders 80 and 81 is mounted for angular adjustmentrelative to the as sociated disc 93. Thus, each disc 93 is formed withcylindrical collar portion 95 that is pinned by a pin 96 against ashoulder 94 formed on a rod 97 which extends through aligned openings inthe tool holder 80 or 81, the associated disc 93 and the associatedbracket 90. The collar portion 95 of each disc 93 and the shoulder 9 1of each rod 97 fit into a suitable socket formed in the associated toolholder 80 or 81. The rods 97 are threaded at both ends to receive thenuts 98 and 99.

When a nut 98 is loosened,.the tool holder 80 or 81, as the case may be,can be adjusted angularly on the disc 93. When a nut 99 is loosened, adisc 93 can be adjusted angularly with reference to the associatedbracket 90.

Both the adjustment of a tool holder on its associated disc 93 and ofthe disc 93 on its associated bracket 90 tilt the tool holder so, as tochange the inclination of the cutting,

face of the tool from its tip to its base with reference to the plane ofgrinding. The adjustment of the tool holder 80 or 81, as the case maybe, on the associated disc 93, is a very limited adjustment. There is apin 100 (Figs. 2 and 8) threaded into each disc 93 and the head of thispin engages in an arcuate slot 101 formed in the associated tool holderlimiting the movement of the tool holder on the associated disc 93. Whena tool of 14 /9 pressure angle is to be sharpened, the tool holder isadjusted to the limit of its adjustment in one direction on the disc 93.This serves to bring the tool into position such that the cutting edgeground upon it will be perpendicular to its line of cut when mounted onthe gear cutting machine. When a 20 pressure angle tool is to besharpened, the tool holder is adjusted in the opposite direction to thelimit of its adjustment on the disc 93. The cutting edge of the 20pressure angle tool will then be ground so that it will be perpendicularto the line of cut of the tool when cutting a gear blank. 14% and 20 arethe two most common pressure angles employed on bevel gear generatingtools. W'here tools of other pressure angles are to be sharpened, thetools can be adjusted into the correct position by adjusting toolholders and discs 93 together onthe associated brackets 90. Theadjoining peripheral surfaces of the discs and of the brackets aregraduated to permit of accurately making the required adjustments. Theseparate adjustments of the tool holders with reference to theassociated discs 93 and of the respective discs 93 with reference to thecorresponding brackets 90 are provided simply as a matter of conveniencefor the complete adj ustment might be made by simply adjusting each toolholder with its disc on the bracket 90. The adjustment of the toolholders and discs 93 together on the associated brackets 90 is ofsuflicient latitude to allow positioning a tool of any pressure angle,also, so as to grind the tool with a hook.

Each of the brackets 90 is adjustable angularly on an associated disc105. The discs 105 are in turn adjustable vertically on guide surfaces107 which are cast integral with the sleeves 108 that fit on therespective posts 109. There is a tongue 106 formed on each disc 105which engages in a groove 111 of the associated guide surface 107 toguide the disc 105 in its adjustment on that plate. Each bracket 90 issecured in any position of its angular adjustment on the associated disc105 and each disc 105 is secured in any position of its verticaladjustment on the associated guide plate 107 by a screw member 112 whichthreads into the angle bracket 90 and passes through an opening in theassociated disc 105 and through an elongated slot 114: in the associatedsleeve 108, and which has a nut 115 threaded on its outer end.

The purpose of the angular adjustment of the bracket 90 on the disc 105is to enable positioning the tool to be ground so as to grind other thana standard shear or rake angle on the tool as may be required to meetexceptional cutting conditions. The contiguous peripheral surfaces ofthe disc and bracket are graduated to allow this adjustment to beaccurately made. The adjustment of a disc 105 on the associated guidesurface 107 is to permit bringing the face of the cutting tool into thegrinding plane after the other adjustments have been made.

To increase the range of vertical adjustment of the tool holders thesleeves 108 are constructed, also, so that they are verticallyadjustable on associated posts 109 which carry the complete toolsupports. Each sleeve 108 is adjusted on its associated post 109 inexactly the same way as the sleeve 120 which carries the face millcutter support is adjustable on its post 109 and reference may be had toFigures 1 and 13, in which the latter adjustment is shown, for anunderstanding of the manner in which each sleeve 108 is adjusted on itspost 109.

There is a screw shaft- 121 secured in a cap 122 that is secured to eachof the sleeves 108 and 120 by screws 12?. Each of the screw shafts 121is provided with a shoulder 123 that fits against the lower face of thecap 122 and a handwheel 125 is keyed to the screw shaft 121 above theassociated cap 122. The handwheel is secured on the screw shaft by'a nut126. The caps 122 are secured to their respective sleeves 108 and 120 byscrews 127. Each of the screws 121 threads into a nut 130 that restsupon the upper face of the associated post 109 but is not secured tothat post. Each of the nuts 130 carries a pin 131 that is adapted totravel in a groove 132 cut vertically in the inside wall of the sleeve108 or 120 as the case may be. The pins 131 serve to hold the associatednuts 130 against rotation relative to the associated sleeves 108 or 120so that when the associated handwheels 125 are rotated, the sleeves willbe'adjusted vertically on the associated posts 109. At the same time,inasmuch as the nuts 130 are not connected to the post 109, the sleeves108and 130 can be oscillated on their associated posts 109 withoutchanging the position of vertical adjustment of the sleeves on theposts. Each of the posts 109 is bored as indicated at 133 so as to allowpassage of the screw shaft 121 down into the post in the process ofvertical adjustment of the sleeve on the post.

The posts 109 which carry the supports for the reciprocatory tools aremounted with a driven lit in the post openings at either side of thecentral plane of the machine. There is a hand-grip or bar 135 secured ineach of the sleeves 108 and the operator of the machine grasps these toswing the sleeves 108, and, with the sleeves, the associated toolholders about the axes of the post 109 to move the front faces of thecutting tools across the surface of the grinding wheel.

The grinding wheel is secured to the grinding wheel spindle 25 by a disc140, a washer 14:1 and a nut 142. The nut 142 threads on to the lowerend of the spindle 25 and the grinding wheel is clamped against a collar143 which is formed at its rear face to constitute part of the labyrinthseal for the anti-friction bearings 27 and which is held againstrotation with reference to the spindle 25 by a set-screw 1 14. Ingrinding reciprocatory tools, a cup-shaped grinding wheel is pref--erably employed. Such a wheel is shown at 1&5 in the drawings.

To grind a pair of reciprocatory tools, the two tools of the pair aresecured in the sockets 82 of the respective tool holders and 81, beingclamped in place by the clamping screws 84. The tool holders areadjusted angularly on the associated discs 93 to one limit or the otherof adjustment of the tool holders on the discs if 14 or 20 pressureangle tools are to be sharpened. If the tools are of some other pressureangle or if it is desired to grind the tools with a hook, the discs 93together with the tool holders will be adjusted angularly directly onthe associated brackets 90. If the rake or shear angle of the tools isstandard, no angular adjustment of the brackets 90 on the discs 105 isnecessary. The

inclination of the sockets 82 of the tool holders takes care of thisadjustment. If any other than a standard rake angle is desired, then thebrackets will be adjusted on the discs 105. When the required settingadjustments have been made, the discs are adjusted on the guide plates107- and the sleeves 108 on the posts 109, to bring the front faces ofthe tools into the grinding plane, that is, into the plane of the tipsurface of the cup-shaped wheels 145.

When the various adjustments have been made and the wheel 1 15 has beensecured to the grinding spindle 25, the operator starts the machine.This causes the grinding wheel spindle to be rotated from the motor 10through the pulleys 11, 13 and 35 and the belt 12. Coolant is pumpedonto the Wheel from the pump 51 which is driven from the grinding wheelspindle through the pulleys 31 and 63 and the belt 62. The operatorstands in front of the machine and grasps the two handles 135 and herocks these handles toward and away from each other, thus moving thefront faces of the tools across the tip surface of the rotating grindingwheel, thus grinding back these surfaces to sharpen the tools. The toolsare advanced into the wheels to grind off the desired amount of stock byrotating the handwheels 125 to adjust the sleeves 108 vertically on thepost 109. Mention is again made of the fact that the rocking of thetools across the face of, the grinding wheel does notaflect theadjustment of the sleeves 108 on the post 109 for the nuts 180 simplyfit on top of the post and are not secured thereto.

I shall now describe the support which is provided for mountingface-mill gear cutters so as to sharpen such cutters on a machineconstructed according to this invention. The hole 70 in which the post109 that carries the face mill support is inserted is considerably toone side of the central plane of the machine. The sleeve which carriesthe face mill cutter support is adjustable on the associated post 109through rotation of the handwheel as already described. This sleeve 120is formed at one side'with a flat guide surface (Figs. 3 and 6). Anangular bracket 152 is mounted on the sleeve 120 for linear adjustmenton the guide surface 150. The angular bracket 152 is secured in anyposition of its adjustment on the plate 150 by a bolt 154 which engagesin the plate 150 and passes through an elongated slot 155 formed in thebracket 152. The plate 150 is formed with a tongue 156' which engages ina correspondingly shaped groove in the brackct 152 to guide the bracketin its adjustment on the plate.

The bracket 152 is formed with an arm 158 (Figs. 3, 4 and 6) that isformed to provide a sleeve or hearing portion 160. The arm portion 158of the bracket is formed, also,

with a plate 161 which projects beyond the sleeve or bearing portion ofthe bracket.

The cutter carrier 162 is mounted for rotatable adjustment in thebearing portion 160 of the bracket 152, the carrier 162 being providecfor this purpose with a stem portion 163 which is journaled in thesleeve or bearing portion 160. The cutter spindle 165 is rotatablymounted in a bushing 166 in the cutter carrier 162. The face mill cutterto be ground is secured to the spindle 165 by any suitable means.

The smaller sizes of face mill cutters have the cutting blades formedintegral with the j cutter heads but the larger sizes of cutters are ofthe inserted blade type, the blades being removable and being secured inslots in the periphery of the cutter heads. One of the larger sizes offace'mill gear cutters is shown ,7

in the drawings. This cutter comprises the cutter head 167 and theremovable cutting blades 168 which are secured to the cutter head byscrews 169. The blades 168 of the cutter are relieved both on theirsides and tips from front to rear to provide the cutting clearance. Eachof the cuttingblades may be made so that it cuts on two sides but thepresent standard practise is to make the cutters so that alternateblades cut opposite sides of the gear teeth. This means that thethickness ofeach blade is slightly less than the thickness of the toothslots to be cut and that alternate blades are provided with a front rakeor shear angle extending in opposite directions, one blade being given afront rake to provide a cutting edge at one side and the next bladehaving a front rake which provides a cutting edge at the opposite side.One of the blades is shown in Figure 14. Here the front face 170 of theblade is inclined to the side face 171 at an acute angle to provide aside cutting edge indicated at 17 2. The blades may-or may not beprovided with a hook depending upon the material in the gears to be cut.

In the drawings, the cutter to be'ground is shown secured to the spindle165 by a ring member 17 5 which hasits periphery tapered to correspondto the taper of the bore of the cutter head 167. This ring member 175fits over the nose of the spindle 165 and is secured to the spindle byadjusting screws 176.

designates a notched index plate, the

its

number of notches 181 (Figs. 3, 4: and 5) in 1 this plate is equal tothe number of the blades in the cutter head if all of the blades havetwo cutting edges-or if all of the blades have cutting edges on the sameside. The number of notches 181. in the index plate is equal to halfgrinding of the different cutters which are within the capacity of themachine.

; 9 end of the bore of the projection 1.97. This .7 The index platebeing used is pressed on to the spindle 165 against the shoulder 183thereof. The index plate 180 has clutch teeth 184 on its rear face.There is a sleeve 185 mounted on the spindle 165 behind the index plate180. This sleeve is formed with clutch teeth on its front face which areadapted to engage the clutch teeth 184 of the index plate 180. Thesleeve 185 isslidable on the spindle 165 to engage or disengage theclutch teeth of the sleeve and the index plate. There is a spring 187which surrounds the spindle 165 and which is interposed between thesleeve 185 and the index plate 180 and which tends to move the sleeveaway from the index plate to disengage the clutch teeth.

Keyed to the spindle 165 behind the sleeve 185 is an adjusting collar188. The collar 188 is formed with ears 189 and 190 (Fig. 4) into whichthread the adjusting screws 191 and 192. These screws engage oppositeside faces of the lug 194 formed on the sleeve 185; The adjusting collar188 is adjustable axially on the spindle 165 by means of a screw 195which is mounted in the guide 196 that is pressed into the collar 188and which threads into the end of the spindle 165.

. The carrier 162 is formed with a projection 197 that is bored to housethe index locking plunger 198. The tip of this plunger is formed so asto engage in the notches 181 of the index plate 180 to lock the indexplate against movement relative to the carrier 162 in one direction butto allow the index plate to be ratcheted around in the oppositedirection. The locking plunger 198 is constantly urged into lockingposition by the coil spring 199 which is interposed between the plunger198 and the cap 200 which closes the outside cap is secured in positionby screws 202.

When the screw 195 is threaded up, the collar 188 will force the sleeve185 forward against'the resistance of the spring 187 to engage theclutch teeth of the sleeve 185 with the clutch teeth 184 of the indexplate 180. Thus the index plate 180 will be secured to the sleeve 185.The sleeve 185 is secured against rotation relative to the collar 188 bythe screws 191 and 192 when these screws are adjusted into engagementwith the ear or lug 194 of the sleeve 185. When the locking plunger 198is engaged with one of the notches 181. of the index plate 180', theindex plate will be secured to the cutter carrier 162 and since theindex plate is secured by the clutch to the sleeve 185 and by thecollar188 to the spindle 165, the spindle 165 will be locked in one directionagainst rotation relative to the carrier 162. Thus the face mill cutterwhich is secured to the spindle 165 will be held against rotation in onedirection with one of its blades in position to be sharpened.

WVhen one of the blades of the cutter has been sharpened the cutterspindle is indexed to bring another blade into grinding position. Thisis done simply by rotating the collar 188 in one direction to cause thelocking plunger 198 to ratchet out of the notch 181 of the index platewith which it has previously been engagedand drop into the next notch ofthe plate.

The grinding wheel which is used for grinding face mill cutters is ofdished shape. This type of wheel is used in order to clear the cutterhead. The same type of wheel might be used for grinding thereciprocatory tools but it is preferred to use a cupped wheel for thislatter purpose because such a wheel does not change in diameter as it isdressed. The dished wheel 210 is secured to the grinding wheel spindle25 in the same manner as the cup shaped wheel, namely, by the nut 142,washer 141 and clamping disc 140.

The cup shaped wheel can be dressed with a hand dresser of any suitabletype. For dressing the dished wheel, there is a dressing device securedto the face-mill cutter carrier 162. This latter dressing devicefunctions not only to keep the wheel 210 in shape but also as a gauge toenable the cutter to be adjusted accurately into the two positions whichit occupies, respectively, when the outside cutting blades and theinside cutting blades are being sharpened.

The dressing'device for the dished wheel comprises a diamond that ismounted in a suitable holder 212 (Figs. 3 and 7). Theholder 212 isclamped in an arm 213 by a screw 214, the arm being formed at its outerend as a split-clamp. The arm213 is mounted for swinging adjustment on abracket 215. The bracket 215 is double-armed. One arm is adjustablysecured to a plate 217 that is formed inte ral with the carrier 162 atone side thereof; This arm of the bracket 215 is formed with a footportion 218 that is provided with a tongue 219' that engages in acorrespondingly shaped elongated groove in the plate portion 217 of thecarrier. The plate portion 217 of the carrier is formed with anelongated slot 220 that communicates with the groove in which the tongue219 fits. The bracket 215 is secured to the plate 217 by a bolt 222which passes through the slot 220 of the plate member and threads intothe bracket. A set-screw 223 is provided to lock the bolt 222 againstrotation once the adjustment of the bracket 215 on the plate portion 217has been made. The adjoining surfaces of the bracket and the plateportion 217 are graduated to permit this adjustment to be accuratelymade.

There is a plug-gauge 225 secured in the outer end of the other arm ofthe bracket 215. This serves for setting the diamond holder 212 in thearm 213 for height.

The arm 213 is secured to the bracket 215 by the clamping screw 227.When the wheel is to be dressed, the arm 213 is swung into the positionshown in Figure 3 and clamped there by the screw 227. When the diamondis to be gauged, the arm 213 is swung inwardly to bring the diamond intocontact with the plug-gauge 225. During actual grinding, the arm 213 isclamped in inoperative position shown in Figure 7 by the screw 227.

In setting up the machine to grind a face mill cutter, the posts 109which carry the re clprocatory tool holders are removed from their holesand the post 109 which carries the face mill cutter holder is insertedin its hole 70. The angle bracket 152 is then adjusted on the plate inaccordance with the diameter of the cutter to be sharpened. The bracket152 is suitably graduated as shown in Figure 3 to enable this adjustmentto be accurately made. When the adjustment has been made, the anglebracket is secured in adjusted position by tightening up the bolt 15%.The cutter carrier 162 is then adjusted angularly in the bearing portionof the angle bracket 152 to tilt the cutter so that the blades will beground with their cutting edges perpendicular to the plane of cut orwith a hook as may be desired. This adjustment is made by adjusting thesetscrews 230 and 231 (Figs. 4: and 6) which engage with the stud 233(Figs. 3, 1 and 6) that is threaded into the stem portion 163 of thecutter carrier. To enable this "adjustment to be made accurately, hereis an arm 235 pinned to the stem portion 163 of the cutter carrier andthis arm is provided on its periphery with an index mark which readsagainst peripheral graduations on the arm 161 which extends from theangle bracket 152. The screws 230 and 231 thread into lugs or cars 237formed in opposite sides of a circular projection 238 formed on thebearing portion 160 of the bracket 152. The stud 233 extends centrallyinto the openingin the bearportion 160 formed by the circular projection238. The carrier 162 is clamped in any position of its angularadjustment by the clamping screw 2&0 (Figs. 1 and 6) which ismanipulated by the lever 2&1. The head of the screw engages against theperiphery of the stem portion 160 of the carrier 162.

The diamond carrying bracket 215 is now adjusted on the plate portion217 of the carrier 162 depending upon whether the outside or insidecutting blades of the cutter are to be sharpened first. r hecontiguous'surfaces of the plate portion 217 and of the foot portion 218of the bracket 216 are graduated to enable the adjustment to be madeaccurately. The arm 213 is then swung to carry a diamondholder over thegauge-block 225 and the diamond iolder 212 is adjusted in the arm 213until the diamond engages this block. The diamond holder is then swunginto dressing position, corresponding to that shown in Fi ure 3, and thearm 213 clamped in this position by the screw 227.

The grinding wheel 210 is now started up and the handwheel 125 rotatedto adjust the sleeve 120 on the post 109 until when the cutter carrieris swung about the axis of the index plate 180 and the spindle is rd 3tated by turning the collar 188 until one of the outside or'one of theinside bladesof the cutter, depending upon the previous setting of thediamond, is as close as possible to the working surface of the grindingwheel. 7

If the The clutches are then retightened.

cutting edge of the blank is slightly away from the grinding wheel afterthe clutches have been retightened it can be brought against the wheelby adjusting the feed screws 191 and 192.

There is a bracket 250 (Figs. 3 and 4-) secured to the base or frame ofthe machine by screws 251. This bracket is formed with an arm, the outerend of which is split to provide a split clamp that is closed by a screw252. There is a stop screw 254 threaded into the arm of the bracket andit is clamped in any adjusted position by tightening up on the screw252. The stop screw 254 is adapted to engage a lug 255 formed on thesleeve 120 when the cutter carrier'is swung in one direction aboutthe-axis of the post 109 to limit the inward movement of the cutter.

The screw 25 1 is adjusted to allow the out ter carrier to swing in justfar enough for the grinding wheel to grind to the bottom of the 3cutting portion of the blades of the cutter but not to grind into thecutter head. The head of the screw 254; will allow thecutter to be swungfar enough away to clear the wheel.

New with the grinding wheel rotating and the coolant being pumped on tothe wheel. the cutter carrier is swung about the axis of the post 109 togrind the face of one of the blades of the cutter. The correct amount ofstock can be taken oil' of the blades by adjustmentof the feed screws191 and 192. Aftor one of the blades has been ground, the cutter spindleis indexed by grasping the collar 188 and turning the collar in suchdirection as to cause the locking plunger 19'? to ratchet out of one ofthe notches of the index plate and drop into the next notch. The nextsimilar blade of the cutter is then ground by swinging the cuttercarrier into the grinding wheel as before. This swinging movement is amanual operation and the operator may grasp any convenient part of thecutter carrier in order to swing it as, for instance, the collar 188. 7

When all of the outside blades of the cutter have been ground, forinstance, the carrier 162 is adjusted in the bearing portion 160 of theangle bracket 152 to adjust the cutter angularly to grind the oppositeangle of rake on the front faces of the inside cutting blades. Thisadjustment is effected by loosening up on the screw 2 10 (Figs. 4 and 6)and adjustingthe screws 230 and 231, the amount of adjustment beingdetermined by reading the graduations on the periphery of the arm 161.The bracket 215 which carries the diamond is then adjusted on the plateportion 217 of the cutter carrier 162 to set the dia mond for the insideblade. The diamond is checked against the gauge 225, as before and thenswung into dressing position and locked there by the screw 227. Thehandwheel 125 is rotated to bring the diamond into dressingengagementwith the grinding wheel and the grinding wheel is dressed. Thediamond carrying arm 213 is then swung out of the way and locked ininoperative position by the screw 227. The clutch is opened and thecutter spindle 165 rotated to bring one of the inside blades of thecutter as close as possible to the grinding wheel. The clutch is thenlocked up again and the blades brought into engagement with the grindingwheel by adjusting the screws 191 and 192. The inside blades are ground,indexing between blades, as before.

The drawings illustrate the grinding of one hand of cutter. To grind acutter of the 0pposite hand, the grinding wheel is inverted on thegrinding wheel spindle 25, the dia mond carrying arm 213 is inverted onthe bracket 215 so that the diamond is gauged against the opposite endof their plug-gauge 225 and the index locking plunger 198 is turnedaround in the bore of the extension 197 so that when the cutter spindleis turned in the correct direction, the locking dog will ratchet out ofthe notches 181 of the index plate 180. The locking pawl 198 can beturned around in the housing 197 when the cap 200 has been removed.

During the grinding operation on either reciprocatory or face millcutters, the coolant is constantly supplied to the grinding wheel. Itdrops off the wheel into atrough formed in the base of the Ina-Chine(see Fig. 1) and flows into a well 262 formed into the base of themachine through an opening 260 in the removable cover plate 261 of thewell. The well 262 is connected with the reservoir 60 through an opening263 in a sheet-metal partition 261 that is held in position between thewell and the reservoir by a spring-clip 265. To keep the scum on thecoolant in the well from getting into the coolant in the reservoir,there is a guard 267secured to the partition 264 in such spaced relationto the partition as v mal level of water or other coolant in the wellinto the opening 263 in the partition. Thus the water that flows fromthe well 262 back into the reservoir is taken from below the level ofthe scum on the water in the well.

The reservoir 60 is provided with an inclined bottom shown in Figures 1and 12 and can be drained through the duct 27 0 Which leads to one sideof the base 20 of the machine. The duct 270 is closed by a swinging gatemember 272 that pivots on a bolt 273 which is threaded into the base ofthe machine and is provided with a hooked portion 274 that is engaged bythe head of the bolt 275 which also threads into the side of themachine. To drain the reservoir 60, the gate is swung upwardly about itspivot bolt 273. To clean the Well out, the gate is entirely removed byremoving the bolt 273.

From the preceding description it will be seen that a compact machinehas been provided which enables either reciprocatory tools or face millgear cutters to be Wetground. Y'Vhile particular embodiments of theinvention have been described, it will be understood that variousmodifications of the invention are possible and that this application isintended to cover any adaptations, uses, or embodiments of the presentinvent on following, in general, the principles of the invention andincluding such departures freni the present disclosure as come withinknown or customary practise in the gear art and as may be applied to theessential features hereinbefore set forth and as fall Within the scopeof the invention or the limits of the appended claims.

Having thus described my invention, What I claim is:

1. In combination, a frame provided with a plurality of sockets, agrinding Wheel spindle journaled in the frame, a plurality of toolholders constructed to hold, respectively, dif ferent types of tools,each of said tool holders comprising a post adapted to be mountedremovably in one of the sockets in the frame to extend in parallelismwith the grinding wheel spindle, a sleeve mounted on the post for manualoscillation about an axis parallel to the axis of the wheel spindle andadjustable thereon in the direction of its axis of oscillation, and atool support adjustable angularly on the sleeve.

2. In a machine for sharpening gear cut ting tools, a frame, a rotatablegrinding wheel spindle journaled in the frame, a grinding wheelremovably secured thereto, a post mounted in the frame and extending inparallelism with the grinding wheel spindle, a sleeve mounted on thepost, a nut mounted on the post, and having a splined connection withsaid sleeve to rotate with said sleeve and to be movable axiallyindependently of said sleeve, a screw carried by the sleeve adapted tothread into said nut for adjusting the sleeve axially on the post, and atool holder carried by the sleeve and adjustable thereon to permitadjusting the tool carried thereby in accordance with the shear angleand inclination of the cutting edge of the tool to be ground, means forrotating the grinding wheel spindle, and means for continuouslysupplying a coolant to the grinding wheel during rotation thereof.

3. In a machine for sharpening gear cutting tools comprising a frame, arotatable grinding wheel spindle journaled in the frame with its axisvertical, a grinding wheel removably secured to said spindle, a postsecured in the frame and extending in parallelism to the grinding wheelspindle, a sleeve oscillatably mounted on the post, means for adjustingthe sleeve vertically on the post, a bracket angularly adjustable on thesleeve, a tool holder adjustable angularly on the bracket about an axisextending at right angles to the axis about which the bracket isadjustable, said sleeve being oscillatable on the post to move the toolacross the face of the wheel to sharpen the same, means for rotating thegrinding wheel spindle and means driven thereby for continuouslysupplying a coolant to the grinding wheel during rotation thereof.

4:. A machine for sharpening gear cutting tools comprising a frame, agrinding wheel spindle journaled in the frame with its axis vertical, avertical post secured to the frame, a sleeve mounted on the post foradjustment in a direction parallel to the axis of the wheel spindle,said sleeve being also oscillatable on said post about a vertical axisindependently of its adjustment, and a tool support mounted on saidsleeve for angular adjustment thereon in two directions at right anglesto one another.

5. A machine for sharpening gear cutting tools comprising a frame, agrinding wheel spindle j ournaled in said frame with its axis vertical,a vertical post secured to the frame, a sleeve mounted on the post foradjustment in a direction parallel to the axis of the wheel spindle,said sleeve being also oscillatable on said post about a vertical axisindependently of its adjustment, a tool support mounted on said sleevefor angular adjustment thereon in two directions at right angles to oneanother, a cutter spindle rotatably mounted in said tool support, andmeans for indexing said cutter spindle.

6. In a machine for sharpening gear cutting tools, a frame, a rotatablegrinding wheel spindle journaled in the frame with its axis vertical, agrinding wheel removably secured thereto, a vertical post mounted in theframe, a sleeve mounted on the post, a nut resting on the top of saidpost and having a splined connection with said sleeve to rotate withsaid sleeve and to be movable axially independently of the sleeve, ascrew carried by the sleeve adapted to thread into said nut foradjusting the sleeve axially on the post and a tool holder carried bythe sleeve, said sleeve being oscillatable to move a tool carried bysaid tool-holder across the grinding wheel.

7. A machine for sharpening gear cutting tools comprising a frame, arotatable grinding wheel spindle journaled in the frame with its axisvertical, a grinding wheel removably secured to this spindle, means forrotating the grinding wheel spindle, a post secured in the frame andextending in parallelism to the grinding wheel spindle, a sleeve mountedon the frame for manual oscillation about an axis parallel to the axisof the cutter spindle, means for adjusting the sleeve vertically on thepost, a bracket mounted on the sleeve for angular adjustment thereonabout an axis at right angles to the axis of oscillation of the sleeve,and a tool holder adjustable angularly on the bracket about an axisextending at right angles to the axis about which the bracket isadjustable.

8. A machine for sharpening gear cutting tools comprising a frame, arotatable grinding wheel spindle journaled in the frame with its axisvertical, a grinding wheel removably secured thereto, a vertical postmounted in the frame, a sleeve mounted on the post, a nut resting on thetop of said post and having a splined connection with said sleeve torotate with said sleeve and to be movable axially independently of thesleeve, a screw carried by the sleeve adapted to thread into said nutfor adjusting the sleeve axially on the post and a tool holder carriedby the sleeve and adjustable thereon about an axis at right angles tothe axis of the sleeve, said sleeve being oscillatable to move a toolcarried by said tool holder across the grinding wheel.

SCHUYLER H. EARL.

